1000ft View Flashcards
What are the layers of the GI Tract?
- Mucosa
- Submucosa
- Muscularis
- Serosa
Mucosa contains epithelium and glands that secrete what?
GLP-1: glucagon-like peptide
CCK: choleystokinin
What type of neurons are in the submucosa?
Autonomic neurons are within the Meissner’s plexus
What nervous system innervates the myenteric plexus?
Autonomic innervation
What is serosa?
Connective tissue that line the surface of the organ
What are the phases of swallowing?
- Oral phase: voluntary
- Pharyngeal phase: voluntary
- Esophageal phase: involuntary
What enzyme is within saliva that helps to break down carbs?
salivary amylase
Salivary glands are innervated by what branch of the nervous system?
Parasympathetic
What muscle will prevent movement of food into the nasal cavity?
Superior constrictor muscle of the pharynx
*uvula also assists to direct food
When the UES closes what should open?
LES
Peristalsis is initiated by
Stretch receptors
The cricopharyngeal muscle helps with what function
Closes the UES during inspiration
What part of the stomach produces the most acid?
Body
What is the Z line of the esophagus?
A demarcation line, the squamocolumnar (SC) junction or “Z-line”, represents the normal esophagogastric junction where the squamous mucosa of the esophagus and columnar mucosa of the stomach meet
How long does food hang out in the stomach?
About 3 hours on average (depends on food type)
The stomach is impermeable to water, but will absorb what?
NSAIDs and ETOH
What cells cause rhythmic depolarization going toward the pylorus to mix the food
Pacemaker cells
The increased pH caused by food hitting the stomach will cause what response?
More gastric juice to be produced
What hormone will decrease motility and emptying during the intestinal phase in the stomach?
Cholecystokinin
What hormone will slow gastric juice release during the intestinal phase in the stomach?
Somatostatin
What helps to release gastric acid?
Histamine
Where is the vomiting center located?
Medula - will induce deep breathing and close to the epiglottis
What cells secrete hydrochloric acid?
Parietal cells
What is the role of hydrochloric acid?
Breaks down food
Breaks up proteins into amino acids
Where is bile produced?
Liver
Bile is released with pancreatic enzymes through what sphincter?
Sphincter of Oddi
What hormone stimulates bile production?
Secretin
What cell type makes up a bulk of the pancreas?
Acini cells
What breaks down starches and glycogen?
Amylase
What is included within the small intestine?
Includes the deuodenum, jejunum, ilium
What is the primary site of chemical digestion and nutrient absoprtion?
Small intestine
What ligament separates the duodenum from the jejunum?
Treitz ligament
What portion of the small intestine accepts chyme from the stomach?
Duodenum
What is the function of enterocytes?
Cover the small intestine and help with absorption and secretion of mucus
Readily absorb water and nutrients –> absorb into venous system and return to portal venous system
Where is magnesium absorbed?
Jejunum and ilium
What is the largest solid organ?
Liver
What ribs protect the liver?
7-11
Does the liver cross the midline?
Yes, it crosses the midline into the LUQ and epigastric region
What are the lobes of the liver?
- Right (Anterior)
- Left (Anterior)
- Caudate lobe (posterior)
- Quadrate lobe (posterior)
What ligament comes off the falciform to support superiorly to the diaphragm?
Coronary ligament
What is the functional unit of the liver?
Liver lobule
Can hepatocytes regenerate?
YES!!
What are sinusoids?
Located within the liver lobule, they are capillaries between the hepatocytes that receive both arterial and venous blood
Where do sinusoids drain into?
Central vein –> hepatic vein –> IVC
What hormone will prompt release of bile to break down fat?
Cholecystokinin
Is the bile more acidic or alkaline?
Alkaline - helps small intestine with emulsifying and absorbing fats
What normally determines osmotic pressure?
Sodium
What substance results from the breakdown of proteins?
Ammonia
The head of the pancreas receives blood from what artery?
Superior mesenteric artery (SMA)
The body/tail of the pancreas receives blood from what artery?
Branches off of the splenic artery
Lipase breaks down
Fat
Amylase breaks down
Carbs
